This study will explore the relations of blue-green algae and chloroplasts with the aid of somewhat unusual biochemical and biological systems, e.g. the relations of polyamines in the Cyanobacterium, Anacystis nidulans, and in the multiplication of turnip yellow mosaic virus (TYMS) in cells of Chinese cabbage. TYMV contains large amounts of the newly synthesized polyamine spermidine, which neutralizes much of the viral RNA. The polyamine, spermine, which is present in the plant, is very low in the virus, although spermine can bind more tightly than spermidine to RNA. Viral RNA is synthesized in the membranes of chloroplasts of Chinese cabbage and we ask, therefore, if the viral spermidine is also a specific product of chloroplasts. Since procaryotic cells cannot synthesize spermine, unlike eucaryotic cells, we ask also if the chloroplasts are not behaving similarly to the procaryotic Cyanobacteria which synthesize spermidine alone. It will be determined if this spermidine is synthesized via enzymes similar to those found in a Cyanobacterium. Two known routes of spermidine biosynthesis, a) via S-adenosylmethionine (SAM) decarboxylase and b) via asparatate beta-semialdehyde, will be examined. The SAM decarboxylase of many procaryotic bacteria is known to differ in significant respects from the comparable eucaryotic enzyme of yeast and mammalian cells. It is asked if a procaryotic enzyme is present in the photosynthetic cells. The virus RNA also terminates in a valine-accepting tRNA at its 3'-end. Spermidine has been demonstrated to be important in tRNA structure and function, and it will be determined if spermidine plays a significant role in the structure and possibly the function of this terminus.